Process for extracting benzols from heavy oils



Nov. 17, 1925- E. A. BARBET PROCESS FOR EXTRACTIG BENZOLS FROM HEAIVY OILS.

Filed Maron 21, 1921 Inveur.

Patented ov. 17, 1962-5.

4EMILE AUGUSTIN BARRET, 0F PARIS, FRANCE. l i

PROCESS EUR EXTRACTING BENZOLS FROM HEAVY OILS.

Application led Iarch 21, 1821. Serial No. 454,214.

(GRANTED UNDER 'rn rnovISIoNsoF THE Ac'r or MARCH s, 1921, 41 sur. L., 1313.)

To all whom t may cncer/n:

Be it known. that I, EMILE AUGUsT1 N BA1:- nE'r, a citizen of the'French Republic, and residing at Paris,France, have invented a certain new and useful Improved Process' for Extracting `Benzols from Heavy Oils, for which I have filed applications in France, Sep-t.V 5, 1913, Patent No. 473,082; Great Britain, May 1'7, 1916,.Patent No. 100,493; Belgium, May 16, 1916, Patent No. 275,692; Italy, May 17, 1916, Patent No. 128, Vol. 458; and inA Spain, Oct. l30, 1917, `P a tent No. 65,646; of which the following 1s a specification.

This invention relates to treating heavy oils which have been employed for the separat-ion from coke oven and like vgases of the volatile constituents contained in them. l It may be stated that a known method involves the thorough Washing of cokeoven gas, and other analogous gases, with a heavy non-volatile tar oil. This absorbs'the substances Which exist as vapors in said gases, and the recovery Iof such absorbed materials, in separated condition, forms the obJect of the present invention. l

According to the invention, the more volatile of the absorbed materials are, by indirect heating, distilled ofl` and separated into their severalcomponents, after which live or superheated steam. is injected into the residual oil in order to expel the naphthalene therefrom. v l

The apparatus, according to the invention, preferably comprises the 'individual' features and arangements hereinafter repasses through the siphon pipe 6 onto a ferred to.

The process and apparatus will be described with reference to the accompanying drawings which show by AWay of example an arrangement of plant which may be emplo ed.

Iyhe figure is a general View of the apparatus. The benzolated oils which. are contained in an upper reservior, not shown in the drawing, enter through the pipe 1. Their rate of delivery is regulatedby a calibrated cock R having a graduated dial or quadrant. 4

Thenjce they. pass into the tubes of the heat exchanger A wherein they are partially heated by the outgoing heavy oilsfrom which the benzols havebeen extracted. .After passing out from A through theplpe 2, they 'last 4serve as a cooling liquid for the coil condenser C whosefunction is hereinafter described. The benzo-lated oils becoming hotter and hotter, pass out from C through thepipe 3, and they pass through the second tubular exchangerk B, and thence'through the pipe 4 they enter finally' the distilling column D.

The top plate on to which the hot benzolated oils are delivered, is a sort of reservoir plate 25 Where the liquid finally. assumes a complete equalit of temperature with the. vapours of distillation. The vapours pass through the reservoir plate by 'Way of a suitable number of chimneys 26. In this plate the oils begin to lose a small pro ortion of their lighter components. T e oils descend through an overflow 5 on to the hooded plates D which are plates similar to those of all continuous-distilling columns; these plates are not numerous. Below these there are several vaporizing plates E. The plates E contain a conside-1'- able volume of liquid and are provided with a. powerful-live steam coil 27 Whose teiliperature must not be less than, and is preferably above`l? C. As a matter of .fact a high temperatiu'e is requiredV not only for expelling the Whole of the benzene, but especially for extracting at the same time the heavier benzols, the toluene, xylol and cu* mene. The oil -descends sucessively from one vaporizing plate to the next, and should arrive1 in a completely exhausted state on the p ate.. I From the vlast plate E the boiling oil 'direct mechanica-l` action. It is advisable to'empl-oy the steam as dry and as hot as possible. The exhaust steam of an engine may be used with. advanta e, so as to utilize its latent heat, but prefera vly after passing it through a live steam tubular superheater before injecting it into Ithel bottom of F.

The mixture of steam and naphthalene va-v pour passes out through the pipe 7 into the coil 7a in the condenser C. It is necessary to liquefy the naphthalene, but is must not be allowed to congeal, and for this purpose apparatus instead of usingwater asa condensing liquid,

use is made as abovestated of the benzolutcd oil which has already been rendered lukewarm to a. greatextent Ain the heat exchanger The. mixture of water and fnaphthalenewhich is condensed in C, passes out throughA 9 into a continuous decanting device servin as a Florentine vessel separating funne The two liquids form two distinct layers which can be :caused to discharge continuously and separately.

The heavy oil deprived of naphthalene issues from the bottom. of F "throughV the siphon pi e 10,- passes through'the heat exchanger and then passes through'tlie pipe 11 to the other heat exchanger A where it restores almost the' whole of' its heat to thel entering benzolated oil.

Then through the pipe 12 it asses to a water cooler G. This cooler is lled with crushed quartz. The heavy oil which is still lukewarm descends through the interstices of the quartz, whilst the cold water ascends in counter current Contact therewith. There is therefore -a cooling action by direct contact, that is to say, with maximum eiiiciency,`and the regenerated and cooled oil .passes nally out through the pipe 13 on its way back tothe in which it is caused to absorb the benzols contained in the oven' ases. Referring again to tli'eA 'comp ex fbenzol vapours which are given off at the top of the distilling column D, it is now neces` sary to separate them into their components,

in other woi'ds, to rectify them.

The benzolated vapourspass out from I) through the pipe 14 and enter the bottom of the rectifyingcolumn H.

The fractionating takes vplace .according to the ordinary principles of ever rectification process; the plate column is surmouiited by a water condenser .K and a cooler L. The liquid condensed in K and a portion of that of -L return through the pipes 16 and 17 to the top of the column H. This is what is known as the reflux, and this reflux constituting a clarifyin or washing liquid, refines the benzolate vapours' which are bubbling up through it, whilst the reflux itself becomes freed from its more volatile elements. In this manner there-is produced a systematic and very sharply defined classication. A

Right at the beginning the more volatile parts consisting of carbon disulphide and other compounds of low boiling point having a garlic-like odour, are drawn from the cooler L through the pipe 18.

A certain proportion of the reflux, which mageos again on three has alreadyi'ibeen. boiled up tec from the upper or four plates, is extrae part of the'column through the pipe 19.

his is benzene, and the boilino` up a ain to which it has'just been subjected), has reed it from the carbon disulphide and the products of onion-like odour. 'It'is cooled in the cooler M and then passes into a test glass N having a constant regulation discharge of the known type.

Lower down, toluene is extracted 'in the same manner through the pipe4 20. Still further down, the xylol is extracted through the pi e 21, and from the base of Hthe heav-` iest distilled products are drawn through the pipe 22. These lastfthree fractions are cooled in the triplescoil cooler P, and they pass out finally through three test glasses of constant regulation similar to the test glass N. Y

Thermometers -T and T, mounted on the rectifying column H, allow the operatorto regulate'with great accuracy. the volume of the respective fractions which pass through 19, 20, 21 and 22. v

stead of sending this liquid into the cooler' P, it is caused to returnthrough the pipe 23'."

Having now described my inventiomwliat I claim as new and desire to secure by Letters Patent is j 9o If too great a proportion of naphthalene is found inthe draw-oill pipe .22,V then in-l VA process which comprises progressively heating a mixture including aheavy nonvolatile oil containing absorbed materials normally present as vapors in coke oven gas,

first by the heat ofthe out-going stripped oil and by the vapors carrying naphthalene coming from the high heating of-such oil as set forth below, thereafter runningI the- 4somewhat preheated oil through a column still including a rectifying column and first heating the same by indirect steam heat to about 160 C., while drawing off the evolved vapors of the lower part of the rectifyiiig column through which such vapors rise, further'heating the unvolatilized oils by blow` ing thereinto superheated steam capable of raising the temperature of said oils to vaporize the naphthalene, and drawing lnfl? the mixed vapors containing naphtlialene and superheated steam and cooling such vapors by indirectl cooling with the lukewarm incoming oils, such vapors being kept se arate from those passed through the rectifying column.

In testimony whereof I have signed myl name to this specification.

EMILE AUGUSTIN BARBET, 

